build(deps): bump github.com/containerd/containerd from 1.6.16 to 1.6.18 (#1637)

Bumps [github.com/containerd/containerd](https://github.com/containerd/containerd) from 1.6.16 to 1.6.18.
- [Release notes](https://github.com/containerd/containerd/releases)
- [Changelog](https://github.com/containerd/containerd/blob/main/RELEASES.md)
- [Commits](https://github.com/containerd/containerd/compare/v1.6.16...v1.6.18)

---
updated-dependencies:
- dependency-name: github.com/containerd/containerd
  dependency-type: indirect
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

go.mod

@@ -39,7 +39,7 @@ require (
 	github.com/Microsoft/go-winio v0.5.2 // indirect
 	github.com/ProtonMail/go-crypto v0.0.0-20220404123522-616f957b79ad // indirect
 	github.com/acomagu/bufpipe v1.0.3 // indirect
-	github.com/containerd/containerd v1.6.16 // indirect
+	github.com/containerd/containerd v1.6.18 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/docker/docker-credential-helpers v0.7.0 // indirect
 	github.com/docker/go-units v0.5.0 // indirect